1. Field of the Invention
The invention relates to a foot covering such as a boot, more particularly to an air-permeable or breathable, waterproof foot covering.
2. Description of the Related Art
In order to achieve moisture or air permeation, most boots have their shells made of natural leather, a moisture-permeable synthetic leather or fabric, or a combination of these materials. These materials are tailored to form pieces of particular shapes and are then bound together by a sewing process. Such shell construction provides good permeability for air and moisture which contributes dryness and comfort in the interior of the boot.
When it is desired to obtain a waterproofing effect, the moisture-permeable material has to be treated by a special process in order to make the upper waterproof, and the stitched seams in the upper should be sealed by using waterproof sealing means, such as a water-proof adhesive coating, an adhesively-bonded waterproofing strap, etc. However, the treatment process of the material is costly and the presence of the waterproof sealing means results in a loss of moisture-permeable or breathable characteristics of the boot.
There is a boot construction in which a sock-like lining sleeve made of waterproof and breathable fabric or the like is used inside the boot. The lining sleeve extends from the upper to the lower of the boot so as to line both the upper and lower. In this construction, both the upper and lower still have to be made of an expensive air-permeable or breathable, waterproof material, and the stitched seams in the upper have to be sealed with a waterproof material in order to provide a water-proofing effect. Otherwise, water or moisture can intrude between the lining sleeve and the upper and between the lining sleeve and the lower, resulting in an increased weight of the boot. In some cases, the water or the wetted part between the lining sleeve and the upper or lower can produce noise when the wearer walks. The same problems exist in a waterproof boot in which a lasted lining sleeve is provided inside a lasted boot in order to achieve a waterproofing effect. This boot still has to employ an upper and lower which is made of an expensive air-permeable waterproof material and whose stitched seams have to be sealed so as to ensure a good waterproofing effect.